Printers, such as thermal transfer label printers, are well known in the art for printing labels. In a typical thermal transfer label printer, a label and a thermal transfer printer ribbon are compressed between a print head and a roller and fed together past the print head. The print head produces sufficient heat in the appropriate locations to transfer the ink from the ribbon to the label to print a label.
Label application mechanisms are available that automatically apply tape and preprinted labels to cylindrical objects, such as bottles, cans, and the like. These systems typically require the object being labeled to be conveyed past the applicator mechanism in order for the mechanism to apply a preprinted label. A finishing device can then press the label to the object.
Label media is typically wound onto a roll and fed into the printer or label application mechanism by an unwind spool assembly that rotatably mounts the roll. The unwind spool assembly rotates to unwind the label media from the roll. Known unwind spool assemblies typically includes a rotatable mounting block that directly mounts the roll or supports a spool containing the roll of label media. The mounting block rotates as the label media unwinds from the roll. In order to reverse direction, and wind label media back onto the roll or spool, known unwind spool assembles are rotatably driven by a stepping motor. Stepping motors add to the complexity of the assembly, and require control circuitry which allows the motor to rotatably drive the mounting block in both an wind and unwind direction.
In addition spools typically forming part of the unwind spool assembly and mounted on the mounting block typically rotate in their entirety as the mounting block rotates. This configuration makes it difficult, if not impossible, to mount a memory cell on the spool which can be consistently read by a stationary reader mounted on the printer or label application mechanism.